Although most photocopy machines make a one-to-one image size with the original, more sophisticated machines are in common usage wherein the image may be reduced in size. Hence, a legal document, for instance, may be placed on a conventional 81/2 .times. 11 sheet. There are many other reasons for size reduction.
Heretofore, the area of the sheet left unaffected by the reduced exposure required interception of the sheet before going through the fusing stage in order to wipe away the residual field, or required the use of special size masters for each size image. Either process is time-consuming and undesirable.
One teaching of a successful commercial machine which eliminates the problem of dark lateral side edges, is U.S. Pat. No. 3,685,894, which provides illumination on the edges whenever the reduced size exposure would otherwise allow the edges to remain dark and fully charged. In that prior patent, the exposure light exposes the tail end of the charged surface moving through, regardless of length.